微波法提取苦瓜叶中总黄酮

介绍了以苦瓜叶为原料用微波法提取总黄酮，通过正交试验对该方法进行了最佳条件的探讨．实验结果表明：以50％乙醇水溶液作提取溶剂，固液比1：35，微波照射2．5min，浸提时间45min，提取温度80℃，苦瓜叶中总黄酮提取率最高．     

溪黄草中总黄酮的微波辅助提取工艺研究

采用分光光度法测定了总黄酮含量,以总黄酮提取率为指标,在单因素试验的基础上,采用正交试验法。考察了微波功率、微波时间、乙醇浓度、料液比等因素对总黄酮提取率的影响．研究得出微波辅助提取溪黄草中总黄酮的最佳工艺条件是：微波功率为中火,微波时间为4min,乙醇浓度为70％,料液比为1：20．经试验验证,在此最佳条件下．溪黄草中总黄酮的提取率为1．15％．     

凤眼莲总黄酮微波提取工艺的研究

对凤眼莲(Eichhornia crassipes)总黄酮的微波提取工艺进行研究,采用微波法,进行提取凤眼莲总黄酮的单因素试验,并在微波法的单因素试验基础上进行正交试验,研究最佳提取条件.结果表明微波法是提取凤眼莲总黄酮的快速方法,其最佳提取条件为微波时间-2min,乙醇浓度-50％,料液比-1∶80,微波火力-中低火.     

表面活性剂协同微波提取布渣叶总黄酮

采用表面活性剂协同微波法提取布渣叶中总黄酮,考察表面活性剂的种类和浓度、微波辐射时间、料液比、pH等因素对提取总黄酮的影响,结合正交实验进行优化.结果表明:最佳工艺条件为表面活性剂选择0.12％的十二烷基硫酸钠,微波辐2.5 min,料液比1∶35 g/mL,pH 5.5.在最佳工艺条件下,黄酮得率为11.33％.与其他提取方法相比,文中方法具有节能省时、黄酮得率高等优点.     

超声波提取黄芪中总黄酮工艺研究

研究比较了超声波法、微波法、乙醇提取法等工艺提取黄芪总黄酮的效果,得出超声波法提取黄芪总黄酮的工艺最佳．以提取温度、提取时间、料液比、乙醇体积分数为考察因素,黄芪总黄酮提取率为考察指标,采用止交试验法优化黄良总黄酮提取工艺．结果表明,最佳工艺条件为：超声波提取温度为65C、提取时间30min、料液比为1：15（g／mL）、乙醇体积分数为65％,总黄酮的提取率为0．418％,是微波提取法的1．31倍,乙醇提取的1．69倍．     

茶叶总黄酮类物质的微波辅助提取研究

采用微波辅助提取茶叶总黄酮类物质,通过单因素实验和正交实验,对影响微波辅助提取总黄酮提取率的因素进行探讨.结果表明:以80％乙醇为提取溶剂,最佳提取工艺条件为:A3B2C3,即微波功率648 W,微波提取时间为4 min,料液比为1∶45 (g/mL),测得茶叶总黄酮提取率为9.54 mg/g,各因素对总黄酮提取率的影响程度为提取功率＞提取时间＞料液比.     

超声波法虎杖中总黄酮提取工艺研究

目的 确定超声波辅助方法提取虎杖中总黄酮的最佳工艺.方法 采用正交实验优化影响虎杖中总黄酮类成分提取的4种主要因素：提取剂（CH3CH2OH）浓度、提取温度、超声时间以及料液比;并以芦丁为标准样品,利用紫外可见分光光度法测定虎杖中总黄酮的吸光度值,为确定最佳提取条件提供参考.结果 通过正交实验得到从虎杖中提取总黄酮的最佳工艺为：乙醇浓度为75％,超声温度为50℃,超声时间为35 min,料液比1∶40,其提取率可以达到7.68％.结论 通过该实验确立了虎杖中总黄酮提取的最优工艺,提取效果良好、操作简便易行,节能环保.     

微波萃取穿心莲中总黄酮的工艺研究

采用紫外分光光度法,以穿心莲中总黄酮提取量为评价指标,对穿心莲进行微波辅助处理,考察微波功率、微波作用时间、溶剂用量、穿心莲粒度、水浸泡时间等因素对穿心莲中总黄酮提取量的影响,单因素实验和正交试验表明：穿心莲中总黄酮提取的最佳工艺条件为微波功率处于中火、微波作用时间4min、溶剂用量固液比1：50、穿心莲粒度为细粉、水浸泡时间60min．     

微波辅助法提取铁苋菜中的总黄酮

以铁苋菜为原料,优化其总黄酮的微波辅助法提取工艺。在单因素试验的基础上,采用正交试验法,考察料液比、微波时间、微波温度、微波功率对提取效果的影响。实验结果表明,铁苋菜总黄酮的最佳微波提取工艺条件为料液比1:40、乙醇浓度50%、微波时间10min、温度50℃。在此条件下铁苋菜总黄酮的提取率为1.296%。该提取方法具有操作简单、提取时间短等优点,适用于铁苋菜总黄酮的提取。     

黄芩总黄酮的提取工艺研究

采用正交试验,以黄芩苷和总黄酮为指标,筛选水煎煮提取工艺,通过提取工艺研究,寻求黄芩总黄酮的最佳提取方法,提取方法的正交试验表明,水煎煮法中A 3B 2C 3D1为最佳提取工艺.获得最佳提取条件:药材粉碎成粗粉,煎煮三次,每次加12倍量水,提取1小时,趁热滤过,合并滤液.优选的工艺稳定可行.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

正~~